Answer :- d

Solution :- The negative sign is just a convention and it signifies that the direction of E is opposite to the direction in which potential increases.

The overall work performed in carrying a 2coulomb charge in a circular orbit of radius 3 m around a charge of 10 coulomb is calculated below.
It is a well-known fact that W=qdv.
Here dV is the change in overall potential. In the circular orbit of r potential at each point is similar.
Most significantly, the value of r is 3.  
The value of dv=0 and hence W=q₀ =0.

 V = Q/(4 πεr), where r = 1m
V = (2 X 10^-9 )/(4 πεx 1) = 18 volts.

From the definition, the work done to a test charge ‘q0 ’from one place to another place in an electric field is given by the formula
W=q₀ x[v_final -v_initial ]
100=4x[v-(-5)]
v+5=25
v=20V
 

V=kq/r
Therefore, V_net =Kx[(2 µc/4) + (3 µc/6)]
=9c10⁹ x10^-6 [1/2+1/2]x10²
=9x10⁵

 

Electric potential is the electric potential energy per unit charge. In equation form, V=U/q, where U is the potential energy, q is the charge, and V is the electric potential. Since both the potential energy and charge are scalar quantities, so does the potential.
And it 's dimension [ L² M¹ T^-3 I^-1 ]

When the charge is given to inner cylinder than there is an electric field is produced between cylinders which is given by
and due to this a potential difference is developed between two cylinders.

When equal charges are given to two spheres of different radii, the potential will be more or the smaller sphere as per the equation, Potential = Charge / Radius.
Since potential is inversely proportional to radius, the smaller radius will have higher potential and vice versa.

By dimensional analysis

but by superposition

Because of the centre of the larger cube lies at a corner of the eight smaller cubes of which it is made
therefore,